[draft] better handle kABI checks

Performing kABI checks on non-RT LTS kernels is necessary. To check
which kernel is which, enforce branch naming in the kernel build script
so that we can determine which "base" branch is being developed.

Once we determine which "base" branch is being developed, we can easily
determine if it is an RT kernel or not. Enable kABI check if it is a
non-RT kernel and also track the upstream git tag from which we branched
off.

Check for the presence of the kernel-dist-git directory and instruct on
how to set it up if absent. The upstream git tag is tracked so that we
can checkout the kernel-dist-git repository to the given dist tag,
ensuring that the kABI check fails only because of a kABI change, and
not because the correct tag wasn't checked out.

Author: thefossguy-ciq

kernel_build.sh

@@ -3,7 +3,25 @@
 
 pwd
 
-BRANCH=$(git branch | grep \* | cut -d ' ' -f2 | sed -r 's/[{}/]/_/g')
+REAL_BRANCH="$(git branch --show-current)"
+# Enforce branch naming so that we can determine
+# 1. If a kABI check is even necessary
+# 2. Which git tag to checkout in the kernel-dist-git
+# Can do with an if but I always get it wrong
+if ! echo "$REAL_BRANCH" | grep -q -E '((ciqlts[0-9]+_[0-9]+(-rt)?|ciqcbr7_9)$|fips-([0-9]+|legacy-[0-9]+)(-compliant|-certified)?/)'; then
+    echo "Unexpected branch name."
+    echo "Either of the following must be present (part of) in the branch name, enforced for kABI check."
+    echo "- 'ciqcbr7_9'"
+    echo "- 'ciqltsX_Y'"
+    echo "- 'ciqltsX_Y-rt'"
+    echo "- 'fips-legacy-X-compliant/'"
+    echo "- 'fips-legacy-X/'"
+    echo "- 'fips-X/'"
+    echo "- 'fips-X-compliant/'"
+    echo "- 'fips-X-certified/'"
+    exit 1
+fi
+BRANCH=$(echo "$REAL_BRANCH" | sed -r 's/[{}/]/_/g')
 
 START=$(date +%s)
 START_MRPROPER=$(date +%s)
@@ -86,14 +104,58 @@ fi
 END_INSTALL=$(date +%s)
 echo "[TIMER]{INSTALL}: $(( $END_INSTALL - $START_INSTALL ))s"
 
-echo "Checking kABI"
-# ../kernel-dist-git/SOURCES/check-kabi -k ../kernel-dist-git/SOURCES/Module.kabi_x86_64 -s Module.symvers || echo "kABI failed"
-KABI_CHECK=$(../kernel-dist-git/SOURCES/check-kabi -k ../kernel-dist-git/SOURCES/Module.kabi_${ARCH} -s Module.symvers)
-if [ $? -ne 0 ]; then
-    echo "Error: kABI check failed"
-    exit 1
+# "temporary" duct tape
+KERNEL_DIST_GIT_TAG=undecided
+CHECK_KABI=undecided
+# TODO: find status of FIPS and CBR and implement it here
+if echo "$REAL_BRANCH" | grep -q 'ciqlts8_6-rt'; then
+    CHECK_KABI=false
+
+elif echo "$REAL_BRANCH" | grep -q 'ciqlts8_8-rt'; then
+    CHECK_KABI=false
+
+elif echo "$REAL_BRANCH" | grep -q 'ciqlts9_2-rt'; then
+    CHECK_KABI=false
+
+elif echo "$REAL_BRANCH" | grep -q 'ciqlts8_6'; then
+    CHECK_KABI=true
+    KERNEL_DIST_GIT_TAG='imports/r8/kernel-4.18.0-372.32.1.el8_6'
+
+elif echo "$REAL_BRANCH" | grep -q 'ciqlts8_8'; then
+    CHECK_KABI=true
+    KERNEL_DIST_GIT_TAG='imports/r8/kernel-4.18.0-477.27.1.el8_8'
+
+elif echo "$REAL_BRANCH" | grep -q 'ciqlts9_2'; then
+    CHECK_KABI=true
+    KERNEL_DIST_GIT_TAG='imports/r9/kernel-5.14.0-284.30.1.el9_2'
+
+elif echo "$REAL_BRANCH" | grep -q 'ciqlts9_4'; then
+    CHECK_KABI=true
+    KERNEL_DIST_GIT_TAG='imports/r9/kernel-5.14.0-427.42.1.el9_4'
+
+else
+    echo "Warning: Could not determine if kABI check was necessary, defaulting to 'no.'"
+    CHECK_KABI=false
+fi
+
+if [ $CHECK_KABI == 'true' ]; then
+    echo "Checking kABI"
+    if [ ! -d ../kernel-dist-git ]; then
+        echo "Error: kernel-dist-git is missing."
+        echo "RUN: 'git clone https://git.rockylinux.org/staging/rpms/kernel.git $(realpath ../kernel-dist-git)'"
+        echo "RUN: 'git -C $(realpath ../kernel-dist-git) checkout $KERNEL_DIST_GIT_TAG'"
+        exit 1
+    fi
+    # make sure we're on the right branch (the commit author is bad at this and this check exists for him)
+    git -C "$(realpath ../kernel-dist-git)" checkout "$KERNEL_DIST_GIT_TAG"
+    KABI_CHECK=$(../kernel-dist-git/SOURCES/check-kabi -k ../kernel-dist-git/SOURCES/Module.kabi_${ARCH} -s Module.symvers)
+    if [ $? -ne 0 ]; then
+        echo "Error: kABI check failed"
+        exit 1
+    fi
+
+    echo "kABI check passed"
 fi
-echo "kABI check passed"
 
 GRUB_INFO=$(sudo grubby --info=ALL | grep -E "^kernel|^index")